Question

If 5x – 3y = 1 and

x - 2y = - 4, then xy = ? .
A 5
B 4
© 6
D 8
E 9

Answer 1

`6`

The answer is C:6

Answer 2

Yeah answer C is right because from question,
5x -3y=1......eq 1
x-2y=-4 ......eq2
From equation 2 too we can write
x = -4 + 2y ... put this x value on eq 1 so
5(-4+2y) - 3y = 1
-20 + 10y -3y=1
Or, 7y=21
So y=21/7=3
And put the value of y on equation 2
x -2 X 3 =-4
Or x= -4+6
So x=2 answer from question too we get value of x and y is 2,3 so
xy= 2X3=6 answer